1. Field of Invention
The invention relates to a liquid crystal display device and an electronic apparatus. More specifically, the invention is related to technology for obtaining a wide viewing angle in a liquid crystal display device using a homeotropic alignment liquid crystal.
2. Description of Related Art
Transflective liquid crystal display devices which include a reflective mode and a transmissive mode are known. In a transflective liquid crystal display device, a liquid crystal layer is interposed between an upper substrate and a lower substrate. A reflecting film with a light transmissive window in a metal film such as aluminum is provided on the internal surface of the lower substrate. The reflecting film functions as a transflective sheet. In this case, in the reflective mode, external light incident from the upper substrate is reflected from the reflecting film on the internal surface of the lower substrate after passing through the liquid crystal layer, then passes through the liquid crystal layer again and is emitted from the upper substrate to contribute to display. On the other hand, in the transmissive mode, the light from a backlight incident from the lower substrate passes through the liquid crystal layer through the window of the reflecting film and is emitted from the upper substrate to the outside to contribute to the display. Therefore, the region of the reflecting film with the window is the transmissive display region and the other region is the reflective display region.
In conventional transflective liquid crystal devices, the viewing angle in transmissive display is narrow. This is because, since a transflective sheet is provided on the internal surface of a liquid crystal cell so that parallax is not generated, only one polarizer provided on an observer side works on the reflective display and the degree of freedom of optical design is small. Therefore, in order to solve this problem, Jisaki et al. suggested a new liquid crystal display device using a homeotropic alignment liquid crystal in “Development of transflective LCD for high contrast and wide viewing angle by using homeotropic alignment”, M. Jisaki et al., Asia Display/IDW'01, P. 133-136 (2001) cited below. The liquid crystal display device has the following three characteristics:
(1) A vertical alignment (VA) mode, in which liquid crystal molecules with negative dielectric anisotropy are vertically aligned on a substrate and the liquid crystals fall by applying a voltage.
(2) A “multi-gap structure” is adopted, in which the thickness (a cell gap) of the liquid crystal layer in the transmissive display region is different from that of the liquid crystal layer in the reflective display region (with respect to this point, refer to Japanese Unexamined Patent Application Publication No. 11-242226).
(3) The transmissive display region is an octagon and protrusions are provided in the middle of the transmissive display region on a counter substrate so that the liquid crystal molecules fall in eight directions in the region.
See also, generally, Japanese Unexamined Patent Application Publication No. 2002-350853.